samedi 20 mai 2017

Around thirty CubeSats were deployed this week from the ISS - International Space Station. Eight of them are equipped with the software developed at EPFL as part of the Swisscube project. (EPFL = École Polytechnique Fédérale de Lausanne).

Image above: The SwissCube, a satellite designed and made by students, was sent to space seven years ago. Image Credit: EPFL.

Code name: QB50. This European research program, launched in early 2016, aimed at deploying 50 miniaturized satellites - the CubeSats - into the Earth's orbit. Their mission is to observe and measure the "thermosphere", between 100 and 600 km above the earth's surface.

Research institutes from as many as 23 countries are participating in it, and since Monday, the International Space Station (ISS) has expelled the results of their work, the Federal Polytechnic said in a statement.

The controls

Seven years ago, EPFL itself sent SwissCube, the first Swiss satellite, designed and produced by students. If the school is not on the trip this time, it is, in a way, in command of eight of the 28 satellites that have joined the orbit this week.

"We have developed a control software - simply called Satellite Control System (SCS) - particularly lightweight and robust," says Muriel Richard, EPFL's Space Engineering Center (eSpace).

Computer code

This software allows you to encode the instructions you want to send to the satellite, to broadcast them when the satellite is flying over a base station, and then to receive feedback in a safe and automated way.

Image above: A pair of CubeSats, with the Earth's limb in the background, moments after being ejected from a small satellite deployer outside of the International Space Station's Kibo laboratory module on Wednesday, May 16, 2017. The tiny shoebox-sized satellites will orbit Earth observing the Earth’s upper atmosphere and interstellar radiation left over from the Big Bang. Over a dozen CubeSats were ejected into Earth orbit this week outside the Kibo module to study Earth and space phenomena for the next one to two years. Image Credit: NASA.

Eight organizations from seven countries (Turkey, Taiwan, South Korea, Israel, Spain, Ukraine and China) have trusted the work of Swiss developers. They adapted according to their needs the computer code created at the EPFL and distributed in the open source mode.

Prototypes

"It's extremely positive and stimulating for our work," says Muriel Richard. The scientist points out that the software can also be used to control larger satellites.

It will be used in particular in the framework of the CleanSpace One project, a satellite that will have the task of de-orbiting Swisscube so that it does not become an additional "space debris". As for the deployment next year of the first two prototypes of a constellation of 60 nanosatellites, organized by ELSE, an EPFL start-up.

vendredi 19 mai 2017

Image above: Astronaut Peggy Whitson during the 200th spacewalk from the International Space Station (Image credit: NASA).

The 200th spacewalk at the International Space Station (ISS) included a new installation on the Alpha Magnetic Spectrometer (AMS) – a particle-physics detector that was assembled at CERN.

On 12 May, Commander Peggy Whitson and Flight Engineer Jack Fischer of NASA conducted the four-hour spacewalk, while ESA astronaut Thomas Pesquet stayed inside the ISS to drive the station arm that positions the two astronauts.

One of their tasks involved replacing a cable with a bus terminator – a type of connector – to carry data between AMS and the space shuttle. During the spacewalk, the AMS team stationed at CERN in the experiment’s Payload and Operations Control Centre (POCC), were able to check that the bus terminator was properly functioning. This connection will be used from 2018, when a new thermal cooling system for the AMS silicon tracker is put into place.

The AMS cooling pump system was developed by the collaboration at CERN, and a similar system is now also used by some of the LHC experiments to cool their trackers. Despite only needing one pump, AMS was flown to space with four. Now, three of the four pumps are no longer functioning and so multiple spacewalks are planned for 2018 to replace these with a new cooling system, which would extend the life of AMS in space by 12 years.

Alpha Magnetic Spectrometer (AMS) on ISS. Image Credit: NASA

AMS was launched in 2011 on the penultimate flight of the Space Shuttle and has been collecting data during the last six years. It is a particle-physics detector looking for dark matter, antimatter and missing matter and also performs precision measurements of cosmic rays. It reached the milestone of recording 100 billion cosmic ray events on 8 May.

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.

A pair of CubeSats, with the Earth's limb in the background, moments after being ejected from a small satellite deployer outside of the International Space Station's Kibo laboratory module on Wednesday, May 16, 2017. The tiny shoebox-sized satellites will orbit Earth observing the Earth’s upper atmosphere and interstellar radiation left over from the Big Bang. Over a dozen CubeSats were ejected into Earth orbit this week outside the Kibo module to study Earth and space phenomena for the next one to two years. Image Credit: NASA.

Space to Ground: A Fleet of CUBESATS: 05/19/2017

Expedition 51 is wrapping up a week of ongoing research into how living in space affects an astronaut’s brain and vision. The International Space Station also boosted its orbit ahead of crew and cargo missions coming and going in June.

NASA astronaut Jack Fischer strapped himself in a device for the NeuroMapping experiment today that tests how the human brain structure and function changes in space. The study also compares brain changes, motor control and multi-tasking when an astronaut is in a free-floating state.

Doctors have noted how microgravity causes a headward fluid shift of blood and other body fluids. As a result, astronaut’s experience face-swelling and elevated head pressure.

The Fluid Shifts study is exploring a way to offset the upward flow using unique suit known as the Lower Body Negative Pressure suit. Commander Peggy Whitson wore the suit today and underwent ultrasound scans and eye checks to help scientists determine its effectiveness against lasting changes in vision and eye damage.

The space station is orbiting a little higher above Earth this week to prepare for the departure of two crew members on June 2. The SpaceX Dragon is due to launch June 1 and arrive at the station three days later. Mission managers are working a plan dependent on an on-time Dragon launch that could see the Orbital ATK Cygnus cargo craft depart in early June or mid-July.

SpaceX is scheduled to launch its Dragon spacecraft for its eleventh commercial resupply mission to the International Space Station June 1 from NASA’s Kennedy Space Center’s historic pad 39A. Dragon will lift into orbit atop the Falcon 9 rocket carrying crew supplies, equipment and scientific research to crewmembers living aboard the station.

Image above: The explosion of a massive star blazes, or a supernova, observed by the NASA Hubble Space Telescope. The bright spot at top right of the image is a stellar blast, called a supernova. The Neutron Star Interior Composition Explored (NICER) investigation, affixed to the exterior of the International Space Station, studies the physics of these stars, providing new insight into their nature and behavior. Image Credits: NASA, ESA, A.V. Filippenko (University of California, Berkeley), P. Challis (Harvard-Smithsonian Center for Astrophysics), et al.

The flight will deliver investigations and facilities that study neutron stars, osteoporosis, solar panels, tools for Earth-observation, and more. Here are some highlights of research that will be delivered to the orbiting laboratory:

New solar panels test concept for more efficient power source

Solar panels are an efficient way to generate power, but they can be delicate and large when used to power a spacecraft or satellites. They are often tightly stowed for launch and then must be unfolded when the spacecraft reaches orbit. The Roll-Out Solar Array (ROSA), is a solar panel concept that is lighter and stores more compactly for launch than the rigid solar panels currently in use. ROSA has solar cells on a flexible blanket and a framework that rolls out like a tape measure. The technology for ROSA is one of two new solar panel concepts that were developed by the Solar Electric Propulsion project, sponsored by NASA’s Space Technology Mission Directorate.

Image above: The Roll-Out Solar Array (ROSA) is a new, more compact solar panel that will snap open in space, a favorable design over the rigid solar panels currently in use, pictured above. Image Credit: NASA.

The new solar panel concepts are intended to provide power to electric thrusters for use on NASA’s future space vehicles for operations near the Moon and for missions to Mars and beyond. They might also be used to power future satellites in Earth orbit, including more powerful commercial communications satellites. The demonstration of the deployment of ROSA on the space station is sponsored by the Air Force Research Laboratory.

Investigation studies composition of neutron stars

What is a Neutron Star?

Neutron stars, the glowing cinders left behind when massive stars explode as supernovas, are the densest objects in the universe, and contain exotic states of matter that are impossible to replicate in any ground lab. These stars are called “pulsars” because of the unique way they emit light – in a beam similar to a lighthouse beacon. As the star spins, the light sweeps past us, making it appear as if the star is pulsing. The Neutron Star Interior Composition Explored (NICER) payload, affixed to the exterior of the space station, studies the physics of these stars, providing new insight into their nature and behavior.

Animation above: The Neutron Star Interior Composition Explored (NICER) payload, affixed to the exterior of the space station, will study the physics of neutron stars, providing new insight into their nature and behavior. Image Credit: NASA.

Neutron stars emit X-ray radiation, enabling the NICER technology to observe and record information about its structure, dynamics and energetics. In addition to studying the matter within the neutron stars, the payload also includes a technology demonstration called the Station Explorer for X-ray Timing and Navigation Technology (SEXTANT), which will help researchers to develop a pulsar-based, space navigation system. Pulsar navigation could work similarly to GPS on Earth, providing precise position for spacecraft throughout the solar system.

Investigation studies effect of new drug on osteoporosis

When people and animals spend extended periods of time in space, they experience bone density loss, or osteoporosis. In-flight countermeasures, such as exercise, prevent it from getting worse, but there isn’t a therapy on Earth or in space that can restore bone that is already lost. The Systemic Therapy of NELL-1 for osteoporosis (Rodent Research-5) investigation tests a new drug that can both rebuild bone and block further bone loss, improving health for crew members.

ISS - International Space Station. Animation Credit: NASA

Exposure to microgravity creates a rapid change in bone health, similar to what happens in certain bone-wasting diseases, during extended bed rest and during the normal aging process. The results from this ISS National Laboratory-sponsored investigation build on previous research also supported by the National Institutes for Health and could lead to new drugs for treating bone density loss in millions of people on Earth.

Research seeks to understand the heart of the matter

Exposure to reduced gravity environments can result in cardiovascular changes such as fluid shifts, changes in total blood volume, heartbeat and heart rhythm irregularities, and diminished aerobic capacity. The Fruit Fly Lab-02 study will use the fruit fly (Drosophila melanogaster) to better understand the underlying mechanisms responsible for the adverse effects of prolonged exposure to microgravity on the heart. Flies are smaller, with a well-known genetic make-up, and very rapid aging that make them good models for studying heart function. This experiment will help to develop a microgravity heart model in the fruit fly. Such a model could significantly advance the study of spaceflight effects on the cardiovascular system and facilitate the development of countermeasures to prevent the adverse effects of space travel on astronauts.

Currently, the life-support systems aboard the space station require special equipment to separate liquids and gases. This technology utilizes rotating and moving parts that, if broken or otherwise compromised, could cause contamination aboard the station. The Capillary Structures investigation studies a new method of water recycling and carbon dioxide removal using structures designed in specific shapes to manage fluid and gas mixtures. As opposed to the expensive, machine-based processes currently in use aboard the station, the Capillary Structures equipment is made up of small, 3-D printed geometric shapes of varying sizes that clip into place.

Using time lapse photography, on-ground research teams will observe how liquids evaporate from these capillary structures, testing the effectiveness of the varying parameters. Results from the investigation could lead to the development of new processes that are simple, trustworthy, and highly reliable in the case of an electrical failure or other malfunction.

Facility provides platform for Earth-observation tools

Orbiting approximately 250 miles above the Earth’s surface, the space station provides views of the Earth below like no other location can provide. The Multiple User System for Earth Sensing (MUSES) facility, developed by Teledyne Brown Engineering, hosts Earth-viewing instruments such as high-resolution digital cameras, hyperspectral imagers, and provides precision pointing and other accommodations.

This National Lab-sponsored investigation can produce data to be used for maritime domain awareness, agricultural awareness, food security, disaster response, air quality, oil and gas exploration and fire detection.

Image above: MUSES hosts earth-viewing tools such as high-resolution digital cameras and hyperspectral imagers and provides precision pointing and other accommodations. It hosts up to four instruments at the same time, and offers the ability to change, upgrade, and robotically service those instruments. Image Credits: Teledyne Brown Engineering.

These investigations will join many other investigations currently happening aboard the space station. Follow https://twitter.com/ISS_Research for more information about the science happening on station.

jeudi 18 mai 2017

Image above: This view of Jupiter, taken by the JunoCam imager of NASA’s Juno spacecraft, highlights Oval BA -- a massive storm known as the Little Red Spot. Image Credits: NASA/JPL-Caltech/SwRI/MSSS/Bjorn Jonsson.

NASA's Juno spacecraft will make its fifth science flyby over Jupiter's mysterious cloud tops on Thursday, May 18, at 11 p.m. PDT (Friday, May 19, 2 a.m. EDT and 6:00 UTC). At the time of perijove (defined as the point in Juno’s orbit when it is closest to the planet's center), the spacecraft will have logged 63.5 million miles (102 million kilometers) in Jupiter’s orbit and will be about 2,200 miles (3,500 kilometers) above the planet's cloud tops.

Juno launched on Aug. 5, 2011, from Cape Canaveral, Florida, and arrived in orbit around Jupiter on July 4, 2016. During its mission of exploration, Juno soars low over the planet's cloud tops -- as close as about 2,100 miles (3,400 kilometers) During these flybys, Juno is probing beneath the obscuring cloud cover of Jupiter and studying its auroras to learn more about the planet's origins, structure, atmosphere and magnetosphere.

Juno Spacecraft Pass of Jupiter. Animation Credits: NASA/JPL

NASA's Jet Propulsion Laboratory, Pasadena, California, manages the Juno mission for the principal investigator, Scott Bolton, of Southwest Research Institute in San Antonio. The Juno mission is part of the New Frontiers Program managed by NASA's Marshall Space Flight Center in Huntsville, Alabama, for the Science Mission Directorate. Lockheed Martin Space Systems, Denver, built the spacecraft. JPL is a division of Caltech in Pasadena, California.

The combined power of three space observatories, including NASA's Hubble Space Telescope, has helped astronomers uncover a moon orbiting the third largest dwarf planet, catalogued as 2007 OR10. The pair resides in the frigid outskirts of our solar system called the Kuiper Belt, a realm of icy debris left over from our solar system's formation 4.6 billion years ago.

With this discovery, most of the known dwarf planets in the Kuiper Belt larger than 600 miles across have companions. These bodies provide insight into how moons formed in the young solar system.

"The discovery of satellites around all of the known large dwarf planets - except for Sedna - means that at the time these bodies formed billions of years ago, collisions must have been more frequent, and that's a constraint on the formation models," said Csaba Kiss of the Konkoly Observatory in Budapest, Hungary. He is the lead author of the science paper announcing the moon's discovery. "If there were frequent collisions, then it was quite easy to form these satellites."

Images above: Hubble spots a moon around the dwarf planet 2007 OR10. These two images, taken a year apart, reveal a moon orbiting the dwarf planet 2007 OR10. Each image, taken by the Hubble Space Telescope's Wide Field Camera 3, shows the companion in a different orbital position around its parent body. 2007 OR10 is the third-largest known dwarf planet, behind Pluto and Eris, and the largest unnamed world in the solar system. The pair is located in the Kuiper Belt, a realm of icy debris left over from the solar system's formation. Images Credits: NASA, ESA, C. Kiss (Konkoly Observatory), and J. Stansberry (STScI).

The objects most likely slammed into each other more often because they inhabited a crowded region. “There must have been a fairly high density of objects, and some of them were massive bodies that were perturbing the orbits of smaller bodies," said team member John Stansberry of the Space Telescope Science Institute in Baltimore, Maryland. "This gravitational stirring may have nudged the bodies out of their orbits and increased their relative velocities, which may have resulted in collisions."

But the speed of the colliding objects could not have been too fast or too slow, according to the astronomers. If the impact velocity was too fast, the smash-up would have created lots of debris that could have escaped from the system; too slow and the collision would have produced only an impact crater.

Collisions in the asteroid belt, for example, are destructive because objects are traveling fast when they smash together. The asteroid belt is a region of rocky debris between the orbits of Mars and the gas giant Jupiter. Jupiter's powerful gravity speeds up the orbits of asteroids, generating violent impacts.

The team uncovered the moon in archival images of 2007 OR10 taken by Hubble's Wide Field Camera 3. Observations taken of the dwarf planet by NASA's Kepler Space Telescope first tipped off the astronomers of the possibility of a moon circling it. Kepler revealed that 2007 OR10 has a slow rotation period of 45 hours. "Typical rotation periods for Kuiper Belt Objects are under 24 hours," Kiss said. "We looked in the Hubble archive because the slower rotation period could have been caused by the gravitational tug of a moon. The initial investigator missed the moon in the Hubble images because it is very faint."

The astronomers spotted the moon in two separate Hubble observations spaced a year apart. The images show that the moon is gravitationally bound to 2007 OR10 because it moves with the dwarf planet, as seen against a background of stars. However, the two observations did not provide enough information for the astronomers to determine an orbit.

"Ironically, because we don't know the orbit, the link between the satellite and the slow rotation rate is unclear," Stansberry said.

Animated Hubble Space Telescope. Image Credits: NASA/ESA

The astronomers calculated the diameters of both objects based on observations in far-infrared light by the Herschel Space Observatory, which measured the thermal emission of the distant worlds. The dwarf planet is about 950 miles across, and the moon is estimated to be 150 miles to 250 miles in diameter. 2007 OR10, like Pluto, follows an eccentric orbit, but it is currently three times farther than Pluto is from the sun.

2007 OR10 is a member of an exclusive club of nine dwarf planets. Of those bodies, only Pluto and Eris are larger than 2007 OR10. It was discovered in 2007 by astronomers Meg Schwamb, Mike Brown, and David Rabinowitz as part of a survey to search for distant solar system bodies using the Samuel Oschin Telescope at the Palomar Observatory in California.

The team's results appeared in The Astrophysical Journal Letters.

The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

You can’t see them, but swarms of electrons are buzzing through the magnetic environment — the magnetosphere — around Earth. The electrons spiral and dive around the planet in a complex dance dictated by the magnetic and electric fields. When they penetrate into the magnetosphere close enough to Earth, the high-energy electrons can damage satellites in orbit and trigger auroras. Scientists with NASA’s Magnetospheric Multiscale, or MMS, mission study the electrons’ dynamics to better understand their behavior. A new study, published in Journal of Geophysical Research revealed a bizarre new type of motion exhibited by these electrons.

Electrons in a strong magnetic field usually exhibit a simple behavior: They spin tight spirals along the magnetic field. In a weaker field region, where the direction of the magnetic field reverses, the electrons go free style — bouncing and wagging back and forth in a type of movement called Speiser motion. New MMS results show for the first time what happens in an intermediate strength field. Then these electrons dance a hybrid, meandering motion — spiraling and bouncing about before being ejected from the region. This motion takes away some of the field’s energy and it plays a key role in magnetic reconnection, a dynamic process, which can explosively release large amounts of stored magnetic energy.

“MMS is showing us the fascinating reality of magnetic reconnection happening out there,” said Li-Jen Chen, lead author of the study and MMS scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

As MMS flew around Earth, it passed through an area of a moderate strength magnetic field where electric currents run in the same direction as the magnetic field. Such areas are known as intermediate guide fields. While inside the region, the instruments recorded a curious interaction of electrons with the current sheet, the thin layer through which the current travels. As the incoming particles encountered the region, they started gyrating in spirals along the guide field, like they do in a strong magnetic field, but in larger spirals. The MMS observations also saw signatures of the particles gaining energy from the electric field. Before long, the accelerated particles escaped the current sheet, forming high-speed jets. In the process, they took away some of the field’s energy, causing it to gradually weaken.

Eploring Reconnection-Guide Field On

Video above: In an intermediate strength magnetic guide field, the electrons spiral along the field, gaining energy until they are ejected from the reconnection layer. Video Credits: NASA's Goddard Space Flight Center/Tom Bridgman.

The magnetic field environment where the electrons’ motions were observed was uniquely created by magnetic reconnection, which caused the current sheet to be tightly confined by bunched-up magnetic fields. The new results help the scientists better understand the role of electrons in reconnection and how magnetic fields lose energy.

MMS measures the electric and magnetic fields it flies through, and counts electrons and ions to measure their energies and directions of motion. With four spacecraft flying in a compact, pyramid formation, MMS is able to see the fields and particles in three dimensions and look at small-scale particle dynamics, in a way never before achieved.

“The time resolution of MMS is one hundred times faster than previous missions,” said Tom Moore, senior project scientist for MMS at NASA’s Goddard Space Flight Center. “That means we can finally see what’s going on in such narrow layers and will be able to better predict how fast reconnection occurs in various circumstances.”

Magnetospheric Multiscale, or MMS spacecrafts. Image Credit: NASA

Understanding the speed of reconnection is essential for predicting the intensity of the explosive energy release. Reconnection is an important energy release process across the universe and is thought to be responsible for some shock waves and cosmic rays. Solar flares on the sun, which can trigger space weather, are also caused by magnetic reconnection.

With two years under its belt, MMS has been revealing new and surprising phenomena near Earth. These discoveries enable us to better understand Earth’s dynamic space environment and how it affects our satellites and technology.

MMS is now heading to a new orbit which will take it through magnetic reconnection areas on the side of Earth farther from the sun. In this region, the guide field is typically weaker, so MMS may see more of these types of electron dynamics.

A team of scientists from Sapienza University in Rome, Italy, and NASA’s Jet Propulsion Laboratory in Pasadena, California, has developed a new approach to assist in the ongoing development of timely tsunami detection systems, based upon measurements of how tsunamis disturb a part of Earth’s atmosphere.

The new approach, called Variometric Approach for Real-time Ionosphere Observation, or VARION, uses observations from GPS and other global navigation satellite systems (GNSS) to detect, in real time, disturbances in Earth’s ionosphere associated with a tsunami. The ionosphere is the layer of Earth’s atmosphere located from about 50 to 621 miles (80 to 1,000 kilometers) above Earth’s surface. It is ionized by solar and cosmic radiation and is best known for the aurora borealis (northern lights) and aurora australis (southern lights).

Image above: Real-time detection of perturbations of the ionosphere caused by the Oct. 27, 2012, Queen Charlotte Island tsunami off the coast of British Columbia, Canada, using the VARION algorithm. Image Credits: Sapienza University/NASA-JPL/Caltech.

When a tsunami forms and moves across the ocean, the crests and troughs of its waves compress and extend the air above them, creating motions in the atmosphere known as internal gravity waves. The undulations of internal gravity waves are amplified as they travel upward into an atmosphere that becomes thinner with altitude. When the waves reach an altitude of between 186 to 217 miles (300 to 350 kilometers), they cause detectable changes to the density of electrons in the ionosphere. These changes can be measured when GNSS signals, such as those of GPS, travel through these tsunami-induced disturbances.

VARION was designed under the leadership of Sapienza’s Mattia Crespi. The main author of the algorithm is Giorgio Savastano, a doctoral student in geodesy and geomatics at Sapienza and an affiliate employee at JPL, which conducted further development and validation of the algorithm. The work was outlined recently in a Sapienza- and NASA-funded study published in Nature's Scientific Reports journal.

In 2015, Savastano was awarded a fellowship by Consiglio Nazionale degli Ingegneri (CNI) and Italian Scientists and Scholars in North America Foundation (ISSNAP) for a two-month internship at JPL, where he joined the Ionospheric and Atmospheric Remote Sensing Group under the supervision of Attila Komjathy and Anthony Mannucci.

“VARION is a novel contribution to future integrated operational tsunami early warning systems,” said Savastano. “We are currently incorporating the algorithm into JPL’s Global Differential GPS System, which will provide real-time access to data from about 230 GNSS stations around the world that collect data from multiple satellite constellations, including GPS, Galileo, GLONASS and BeiDou.” Since significant tsunamis are infrequent, exercising VARION using a variety of real-time data will help validate the algorithm and advance research on this tsunami detection approach.

Savastano says VARION can be included in design studies for timely tsunami detection systems that use data from a variety of sources, including seismometers, buoys, GNSS receivers and ocean-bottom pressure sensors.

Once an earthquake is detected in a specific location, a system could begin processing real-time measurements of the distribution of electrons in the ionosphere from multiple ground stations located near the quake’s epicenter, searching for changes that may be correlated with the expected formation of a tsunami. The measurements would be collected and processed by a central processing facility to provide risk assessments and maps for individual earthquake events. The use of multiple independent data types is expected to contribute to the system’s robustness.

"We expect to show it is feasible to use ionospheric measurements to detect tsunamis before they impact populated areas,” said Komjathy. “This approach will add additional information to existing systems, complementing other approaches. Other hazards may also be targeted using real-time ionospheric observations, including volcanic eruptions or meteorites.”

Observing the ionosphere, and how terrestrial weather below it interfaces with space above, continues to be an important focus for NASA. Two new missions -- the Ionospheric Connection Explorer and the Global-scale Observations of the Limb and Disk -- are planned to launch by early 2018 to observe the ionosphere, which should ultimately improve a wide array of models used to protect humans on the ground and satellites in space.

The Soyuz carry the SES 15 communications satellite for SES of Luxembourg. Built by Boeing with an all-electric propulsion system, SES 15 will provide in-flight Internet connectivity for airline passengers, and support government, networking and maritime customers across North America. SES 15 also hosts a payload for the FAA’s Wide-Area Augmentation System to enhance airline navigation and safety. The Soyuz 2-1a (Soyuz ST-A) rocket use a Fregat-MT upper stage.

Soyuz lifts off from French Guiana with SES-15 at 11:54:53 GMT (7:54:53 a.m. EDT) from the Guiana Space Center in South America.

Soyuz lifts off from French Guiana with SES-15

SES-15 is the 40th satellite to be launched by Arianespace for the European satellite operator SES, following ASTRA 5B – orbited by an Ariane 5 in March 22, 2014.

As the first hybrid satellite in SES’ fleet, SES-15 will offer a mix of wide beam coverage and high throughput (HTS) capacity. The satellite will provide additional Ku-band wide beams and Ku-band HTS capability, with connectivity to gateways in Ka-band.

SES-15 satellite

Positioned at the new orbital location of 129 degrees West, SES-15 will offer extensive coverage over North America, Mexico and Central America, stretching from Arctic Alaska to the South of Panama and from Hawaii to the Caribbean.

SES-15 was built by Boeing in El Segundo, California using the all-electric 702SP platform, and it is the 53rd Boeing-built satellite to be launched by Arianespace.

mercredi 17 mai 2017

Image above: NASA is asking scientists to consider what would be the best instruments to include on a potential mission to land on Jupiter’s icy moon, Europa. Image Credits: NASA JPL.

NASA is asking scientists to consider what would be the best instruments to include on a mission to land on Jupiter’s icy moon, Europa.

NASA Wednesday informed the science community to prepare for a planned competition to select science instruments for a potential Europa lander.

While a Europa lander mission is not yet approved by NASA, the agency’s Planetary Science Division has funding in Fiscal Year 2017 to conduct the announcement of opportunity process.

“The possibility of placing a lander on the surface of this intriguing icy moon, touching and exploring a world that might harbor life is at the heart of the Europa lander mission,” said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate in Washington. “We want the community to be prepared for this announcement of opportunity, because NASA recognizes the immense amount of work involved in preparing proposals for this potential future exploration.”

The community announcement provides advance notice of NASA’s plan to hold a competition for instrument investigations for a potential Europa lander mission. Proposed investigations will be evaluated and selected through a two-step competitive process to fund development of a variety of relevant instruments and then to ensure the instruments are compatible with the mission concept.

Approximately 10 proposals may be selected to proceed into a competitive Phase A. The Phase A concept study will be limited to approximately 12 months with a $1.5 million budget per investigation. At the conclusion of these studies, NASA may select some of these concepts to complete Phase A and subsequent mission phases.

Investigations will be limited to those addressing the following science objectives, which are listed in order of decreasing priority:• Search for evidence of life on Europa

• Assess the habitability of Europa via in situ techniques uniquely available to a lander mission

• Characterize surface and subsurface properties at the scale of the lander

In early 2016, in response to a congressional directive, NASA’s Planetary Science Division began a study to assess the science and engineering design of a future Europa lander mission. NASA routinely conducts such studies -- known as Science Definition Team (SDT) reports -- long before the start of any mission to gain an understanding of the challenges, feasibility and science value of the potential mission. The 21-member team began work almost one year ago, submitting a report to NASA on Feb. 7.

Europa Clipper. Image Credit: NASA

The agency briefed the community on the Europa Lander SDT study at recent town halls at the 2017 Lunar and Planetary Science Conference (LPSC) at The Woodlands, Texas, and the Astrobiology Science Conference (AbSciCon) in Mesa, Arizona.

The proposed Europa lander is separate from and would follow its predecessor -- the Europa Clipper multiple flyby mission – which now is in preliminary design phase and planned for launch in the early 2020s. Arriving in the Jupiter system after a journey of several years, the spacecraft would orbit the planet about every two weeks, providing opportunities for 40 to 45 flybys in the prime mission. The Clipper spacecraft would image Europa’s icy surface at high resolution, and investigate its composition and structure of its interior and icy shell.

Wednesday’s community announcement in no way obligates NASA to solicit future proposals.

Our Cold War history is now offering scientists a chance to better understand the complex space system that surrounds us. Space weather — which can include changes in Earth's magnetic environment — are usually triggered by the sun’s activity, but recently declassified data on high-altitude nuclear explosion tests have provided a new look at the mechanisms that set off perturbations in that magnetic system. Such information can help support NASA’s efforts to protect satellites and astronauts from the natural radiation inherent in space.

From 1958 to 1962, the U.S. and U.S.S.R. ran high-altitude tests with exotic code names like Starfish, Argus and Teak. The tests have long since ended, and the goals at the time were military. Today, however, they can provide crucial information on how humans can affect space. The tests, and other human-induced space weather, are the focus of a comprehensive new study published in Space Science Reviews: https://link.springer.com/article/10.1007/s11214-017-0357-5

Human Activity Impacted Space Weather

“The tests were a human-generated and extreme example of some of the space weather effects frequently caused by the sun,” said Phil Erickson, assistant director at MIT’s Haystack Observatory, Westford, Massachusetts, and co-author on the paper. “If we understand what happened in the somewhat controlled and extreme event that was caused by one of these man-made events, we can more easily understand the natural variation in the near-space environment.”

By and large, space weather — which affects the region of near-Earth space where astronauts and satellites travel — is typically driven by external factors. The sun sends out millions of high-energy particles, the solar wind, which races out across the solar system before encountering Earth and its magnetosphere, a protective magnetic field surrounding the planet. Most of the charged particles are deflected, but some make their way into near-Earth space and can impact our satellites by damaging onboard electronics and disrupting communications or navigation signals. These particles, along with electromagnetic energy that accompanies them, can also cause auroras, while changes in the magnetic field can induce currents that damage power grids.

The Cold War tests, which detonated explosives at heights from 16 to 250 miles above the surface, mimicked some of these natural effects. Upon detonation, a first blast wave expelled an expanding fireball of plasma, a hot gas of electrically charged particles. This created a geomagnetic disturbance, which distorted Earth’s magnetic field lines and induced an electric field on the surface.

Some of the tests even created artificial radiation belts, akin to the natural Van Allen radiation belts, a layer of charged particles held in place by Earth’s magnetic fields. The artificially trapped charged particles remained in significant numbers for weeks, and in one case, years. These particles, natural and artificial, can affect electronics on high-flying satellites — in fact some failed as a result of the tests.

Although the induced radiation belts were physically similar to Earth’s natural radiation belts, their trapped particles had different energies. By comparing the energies of the particles, it is possible to distinguish the fission-generated particles and those naturally occurring in the Van Allen belts.

Van Allen Probes. Image Credit: NASA

Other tests mimicked other natural phenomena we see in space. The Teak test, which took place on Aug. 1, 1958, was notable for the artificial aurora that resulted. The test was conducted over Johnston Island in the Pacific Ocean. On the same day, the Apia Observatory in Western Samoa observed a highly unusual aurora, which are typically only observed in at the poles. The energetic particles released by the test likely followed Earth’s magnetic field lines to the Polynesian island nation, inducing the aurora. Observing how the tests caused aurora, can provide insight into what the natural auroral mechanisms are too.

Later that same year, when the Argus tests were conducted, effects were seen around the world. These tests were conducted at higher altitudes than previous tests, allowing the particles to travel farther around Earth. Sudden geomagnetic storms were observed from Sweden to Arizona and scientists used the observed time of the events to determine the speed at which the particles from the explosion traveled. They observed two high-speed waves: the first traveled at 1,860 miles per second and the second, less than a fourth that speed. Unlike the artificial radiation belts, these geomagnetic effects were short-lived, lasting only seconds.

Such atmospheric nuclear testing has long since stopped, and the present space environment remains dominated by natural phenomena. However, considering such historical events allows scientists and engineers to understand the effects of space weather on our infrastructure and technical systems.

Such information adds to a larger body of heliophysics research, which studies our near-Earth space environment in order to better understand the natural causes of space weather. NASA missions such as Magnetospheric Multiscale (MMS), Van Allen Probes and Time History of Events and Macroscale Interactions during Substorms (THEMIS) study Earth’s magnetosphere and the causes of space weather. Other NASA missions, like STEREO, constantly survey the sun to look for activity that could trigger space weather. These missions help inform scientists about the complex system we live in, and how to protect the satellites we utilize for communication and navigation on a daily basis.

NASA's Van Allen Probes Spot Man-Made Barrier Shrouding Earth

Humans have long been shaping Earth’s landscape, but now scientists know we can shape our near-space environment as well. A certain type of communications — very low frequency, or VLF, radio communications — have been found to interact with particles in space, affecting how and where they move. At times, these interactions can create a barrier around Earth against natural high energy particle radiation in space. These results, part of a comprehensive paper on human-induced space weather, were recently published in Space Science Reviews: https://link.springer.com/article/10.1007/s11214-017-0357-5

NASA's Van Allen Probes Find Human-Made Bubble Shrouding Earth

“A number of experiments and observations have figured out that, under the right conditions, radio communications signals in the VLF frequency range can in fact affect the properties of the high-energy radiation environment around the Earth,” said Phil Erickson, assistant director at the MIT Haystack Observatory, Westford, Massachusetts.

VLF signals are transmitted from ground stations at huge powers to communicate with submarines deep in the ocean. While these waves are intended for communications below the surface, they also extend out beyond our atmosphere, shrouding Earth in a VLF bubble. This bubble is even seen by spacecraft high above Earth’s surface, such as NASA’s Van Allen Probes, which study electrons and ions in the near-Earth environment.

The probes have noticed an interesting coincidence — the outward extent of the VLF bubble corresponds almost exactly to the inner edge of the Van Allen radiation belts, a layer of charged particles held in place by Earth’s magnetic fields. Dan Baker, director of the University of Colorado’s Laboratory for Atmospheric and Space Physics in Boulder, coined this lower limit the “impenetrable barrier” and speculates that if there were no human VLF transmissions, the boundary would likely stretch closer to Earth. Indeed, comparisons of the modern extent of the radiation belts from Van Allen Probe data show the inner boundary to be much farther away than its recorded position in satellite data from the 1960s, when VLF transmissions were more limited.

With further study, VLF transmissions may serve as a way to remove excess radiation from the near-Earth environment. Plans are already underway to test VLF transmissions in the upper atmosphere to see if they could remove excess charged particles — which can appear during periods of intense space weather, such as when the sun erupts with giant clouds of particles and energy.

mardi 16 mai 2017

(Highlights: Week of May 8, 2017) - While preparing for the 200th spacewalk on the International Space Station, the crew members in orbit performed the latest harvest of vegetables grown in space.

NASA astronaut Jack Fischer collected the latest crop of Tokyo Bekana Chinese cabbage for the Veg-03 investigation. Some of this was consumed at meal-time, and the rest sealed for analysis back on Earth. Understanding how plants respond to microgravity is an important step for future long-duration space missions, which will require crew members to grow their own food. Astronauts on the station have previously grown lettuce and flowers in the Veggie facility.

Veggie provides lighting and necessary nutrients for plants by using a low-cost growth chamber and planting pillows, which deliver nutrients to the root system. The Veggie pillow concept is a low-maintenance, modular system that requires no additional energy beyond a special light to help the plants grow. It supports a variety of plant species that can be cultivated for fresh food, and even for education experiments.

Image above: NASA astronaut Jack Fischer checks out his spacesuit while preparing for a spacewalk outside the International Space Station. Image Credit: NASA.

Crew members have commented that they enjoy space gardening, and investigators believe growing plants could provide a psychological benefit to crew members on long-duration missions, just as gardening is often an enjoyable hobby for people on Earth. Data from this investigation could benefit agricultural practices on Earth by designing systems that use valuable resources such as water more efficiently.

NASA astronaut Peggy Whitson worked on setting up the Fluids Integrated Rack (FIR) for a biophysics study on the space station. The FIR is a research facility designed to host investigations into colloids, gels, bubbles, wetting and capillary action, including the phase changes from gas to liquid to solid. It provides a central location on the space station to research complex fluids.

Investigations range from fundamental research to technology development in support of NASA exploration missions and include life support, power, propulsion, and thermal control systems. The FIR minimizes the number of support items sent to the station by using different modules capable of supporting various types of experiments.

Image above: NASA astronaut Peggy Whitson works on the Light Microscopy Module on the International Space Station. The LMM is a flexible state-of-the-art microscope. Image Credit: NASA.

Ground teams commanded another round of NASA's Space Communications and Navigations Testbed (SCaN Testbed) investigation. The SCaN Testbed is a flexible radio system -- designed at NASA's Glenn Research Center in Cleveland -- that conforms to common, non-proprietary standards so agency flight controllers can change the software and how the equipment is used during flight. It would allow spacecraft crews and ground teams to recover from unpredicted errors or changes in the system.

Changing a radio's software after launch would give mission operators on the ground the ability to enhance communication systems for increased data flow and possibly resolve system problems. Using the same hardware platform for various missions and only changing the software to meet specific mission needs would reduce cost and risk. Radio technology designed for use in space could be used on Earth to develop technologically advanced communications products.

Crew members also performed an investigation about the environment in which they live and work from a practical and psychological point of view. The Habitability Assessment of International Space Station (Habitability) gives station residents the opportunity to make observations about the orbiting laboratory they call home.

Image above: Chinese cabbage is grown in the Veggie facility on the International Space station. The sprouts form in a low-maintenance foam pillow and are grown using a special light to help the plants thrive. Image Credit: NASA.

For crew members on long-duration space missions, cabin designs must balance comfort and efficiency. The thoughts and ideas brought forth by the crew can help spacecraft designers understand how much habitable volume is needed, including whether a mission's duration impacts how much personal space crew members need. The crew answers questionnaires and records video tours while making suggestions on layout and internal design. Results from the Habitability investigation will provide insight and contribute to the design of future spacecraft. It may also apply to workers who live and work in confined spaces with limited volume and resources on Earth, such as remote polar research stations, ocean drilling rigs or mines.

Space to Ground: Everything is Awesome: 05/12/2017

Video above: NASA's Space to Ground is a weekly update on what is happening on the International Space Station. Social media users can post with #spacetoground to ask questions or make a comment. Video Credit: NASA.

Animation above: This movie is made of images taken by NASA's Dawn spacecraft, from a position exactly between the sun and Ceres’ surface Animation Credits: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA.

NASA's Dawn spacecraft successfully observed Ceres at opposition on April 29, taking images from a position exactly between the sun and Ceres’ surface. Mission specialists had carefully maneuvered Dawn into a special orbit so that the spacecraft could view Occator Crater, which contains the brightest area of Ceres, from this new perspective.

A new movie shows these opposition images, with contrast enhanced to highlight brightness differences. The bright spots of Occator stand out particularly well on an otherwise relatively bland surface. Dawn took these images from an altitude of about 12,000 miles (20,000 kilometers).

Based on data from ground-based telescopes and spacecraft that previously viewed planetary bodies at opposition, scientists correctly predicted that Ceres would appear brighter from this opposition configuration. This increase in brightness, or "surge," relates the size of the grains of material on the surface, as well as the porosity of those materials. The science motivation for performing these observations is further explained in the March issue of the Dawn Journal blog.

Dawn's observations of Ceres during its more than two years there cover a broader range of illumination angles than almost any body in the solar system. This provides scientists with an opportunity to gain new insights into the surface properties. They are currently analyzing the new data.

Dawn spacecraft. Image Credits: NASA/JPL

The new observations and images were largely unaffected by the loss of function of Dawn's third reaction wheel. The spacecraft is healthy and orients itself using its hydrazine thrusters.

Dawn's mission is managed by JPL for NASA's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team.

SpaceX conducted its sixth launch of the year Monday (May 15, 2017), with a Falcon 9 rocket deploying the Inmarsat-5 F4 communications satellite. Liftoff, from the Kennedy Space Center, was on schedule at the opening of a 51-minute launch window at 19:20 local time (23:20 UTC). The booster – as planned – did not return for a landing due to the performance requirements of the heavy satellite.

Inmarsat-5 Flight 4 Launch Webcast. Video Credit: SpaceX

Inmarsat-5 F4 is the last in a series of four high-power communications spacecraft which Inmarsat will use to support its Global Xpress mobile satellite broadband product.

Inmarsat was founded in 1979 as the International Maritime Satellite Organization, an intergovernmental partnership to provide satellite communications for maritime users. Privatized in 1999, Inmarsat is based in London and provides global broadband and communications services in addition to maintaining public service operations for maritime and aeronautical users.

An artist’s depiction of the Inmarsat-5 F4 satellite in orbit. Image credit: Boeing

The four Inmarsat-5 satellites were built by Boeing. Based around the BSS-702HP satellite bus, each carries eighty-nine Ka-band transponders and is designed for a service life of fifteen years. Envisioned as a three-satellite constellation, the first three satellites were ordered in 2010.

lundi 15 mai 2017

Image above: One of the first proton-proton collisions seen by the ALICE experiment in 2017, on May 13, during the LHC beam commissioning phase. ALICE used these first collisions to fine-tune its equipment and get ready for the new physics season of LHC. (Image: CERN).

Last week, the detectors of the Large Hadron Collider (LHC) witnessed their first collisions of 2017. These test collisions were not for physics research, instead they were produced as part of the process of restarting the LHC. But have patience, data taking for physics will start in another few days.

Since particles began circulating in the large ring once more, the LHC’s operators have been testing and adjusting 24 hours a day to turn the LHC into a veritable collision factory. Their work involves forming trains of bunches, building them up over the next few weeks to several hundred and then several thousand bunches per beam.

To establish this production line of particles, all of the accelerator’s systems must be perfectly adjusted. The LHC is an extremely complex machine comprising thousands of subsystems and it takes weeks to adjust them all.

Image above: This image shows a beam splash, as observed by the ATLAS experiment on 29 April, the day of the LHC restart. The beam splashes are generated by aiming beams at the collimators near to the experiments, in this case 140 metres from the ATLAS interaction point. Once the LHC is back in operation, the experiments use the beam splashes to synchronise their sub-detectors with the accelerator’s clock. (Image: CERN).

The first particles circulated on 29 April 2017 and, soon after, the operators started work on their long list of adjustments. They tested the radiofrequency system, which accelerates the particles. They brought the beam energy up to its operating value of 6.5 TeV. They tested the beam dump system, which ejects the particles into a block of graphite if required. They tested and aligned all the collimators – jaw-like devices that close around the beam to absorb stray particles. They carried out proton bunch ramp and squeeze cycles. Finally, they performed fine adjustments of the hundreds of corrector magnets, adjusting the trajectory of the beam to a precision of one micron at the collision points.

Image above: A beam splash, as observed by the CMS experiment on 29 April. In contrast to proton-proton collisions where the particles come from the center of the detector, in splash events particles traverse the detector horizontally, from one side to the other. (Image: CERN).

Last Wednesday, they started to collide the beams to be able to adjust the interaction points at the heart of the experiments. This step is carried out with so-called “pilot” beams, containing fewer than ten bunches and fewer protons than during the physics runs. These first collisions also allow the experiments to adjust their detectors.

In the coming days, the operators will continue to adjust and align the equipment. Once all of these steps are complete, they will be able to announce “stable beams”, the long-awaited signal for the start of the new data-taking season for the experiments.

Note:

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 22 Member States.